Fig. 11.

Schematic representation of the counteraction of APOBEC3G by Vif. In the Vif+ setting (top), Vif (yellow) induces the proteasomal degradation of APOBEC3G (red star) in the virus-producing cell (left), enabling productive infection to occur in the target cell (right). In the absence of Vif expression (bottom), APOBEC3G is packaged into virus particles, and in the next round of infection induces the deamination of cytosines to uracils, resulting in G-to-A hypermutation. The presence of APOBEC3G also impairs reverse transcription and integration. Reprinted with permission from Elsevier (Freed, 2004).